Field of the Invention
This invention relates to optical detectors. More specifically, the invention is a multi-element optical detector system for imaging and/or sensing applications that detects and/or measures photo-induced electron transfer through micro-scale electron conduction elements (e.g., carbon nanotubes (CNT), photoactive materials having low work functions, or combinations of these two) that are spaced from a bias voltage screen through which radiation of interest passes.
In accordance with the present invention, an optical detector system includes an electrically resistive screen that is substantially transparent to radiation energy having a wavelength of interest. A voltage source is provided to apply a bias voltage to the screen. A plurality of electron transfer elements (e.g., a low work function photoactive material, a carbon nanotube (CNT), or a CNT topped with a low work function photoactive material) are provided with each having a first end and a second end. The first end of each element is spaced apart from the screen by an evacuated gap. When the radiation energy passes through the screen with the bias voltage being applied thereto, transfer of electrons through each element is induced from the first end to the second end thereof. A detector, electrically coupled to the second end of each individual element, detects a quantity indicative of the electrons transferred through each element. The optical detector system can operate as described for imaging applications and can be adapted for sensing applications by providing one or more types of analyte-sensitive, luminescent coatings on the screen.